Search found 4957 matches

by Jirka
Fri Jul 03, 2020 5:02 pm
Forum: HYDRUS (2D/3D)
Topic: Perc test simulation
Replies: 2
Views: 9

Re: Perc test simulation

Please note that we posted almost identical examples (Well-radial) to yours at https://www.pc-progress.com/en/Default.aspx?h3d2-lib-ReservoirBC. What to pay attention to: 1. The z coordinates are the absolute coordinates as used to define the transport domain. If you have the origin of the coordinat...
by Jirka
Thu Jul 02, 2020 10:13 pm
Forum: Soil Physics with Hydrus
Topic: calculation of water and elements fluxes
Replies: 2
Views: 22

Re: calculation of water and elements fluxes

I provide online support only for the applications of the HYDRUS-1D codes. I do not discuss online other soil physics issues. J.
by Jirka
Thu Jul 02, 2020 7:01 pm
Forum: Hydrus 1D
Topic: Solute transport
Replies: 3
Views: 43

Re: Solute transport

You need to specify all boundary fluxes as they occurred (i.e., precipitation, irrigation, etc). In addition, you need to associate your solute application with a water flux such so that you get the right amount (i.e., Conc*Flux*Time) into the soil profile.
J.
by Jirka
Wed Jul 01, 2020 7:41 pm
Forum: Hydrus 1D
Topic: Solute transport
Replies: 3
Views: 43

Re: Solute transport

Solute can enter the soil profile in HYDRUS only as a solute flux. You should use the Cauchy BC and associate your N application with some liquid flux. J.
by Jirka
Wed Jul 01, 2020 5:53 pm
Forum: HYDRUS (2D/3D)
Topic: Well as constant head
Replies: 9
Views: 1121

Re: Well as constant head

I'm not sure what you mean. Linear distribution of the pressure head on the boundary representing the well (in the reservoir BC)? What else would you suggest than using the hydrostatic pressure head? J.
by Jirka
Wed Jul 01, 2020 3:01 am
Forum: HP1 (HYDRUS-1D - PHREEQC)
Topic: Mass balance issue with 'surface layer' boundary
Replies: 4
Views: 41

Re: Mass balance issue with 'surface layer' boundary

You need to copy these files into the HYDRUS folder (where the HYDRUS software is installed). J.
by Jirka
Tue Jun 30, 2020 11:37 pm
Forum: HP1 (HYDRUS-1D - PHREEQC)
Topic: Mass balance issue with 'surface layer' boundary
Replies: 4
Views: 41

Re: Mass balance issue with 'surface layer' boundary

The code was not meant for conditions when the entire profile is fully saturated and simultaneous atmospheric and free drainage BCs. However, we can handle that as well. Try the attached updated code. J. sum(rTop)=137.48 cm (it's negative but to simplify I only keep the absolute values for all resul...
by Jirka
Sat Jun 27, 2020 10:06 pm
Forum: Hydrus 1D
Topic: Soil water evaporation
Replies: 5
Views: 132

Re: Soil water evaporation

As I wrote above, the surface node should be slightly unsaturated. When you have the VG model with an air entry value of -2 cm, i.e., the surface pressure head should be below -2 to make it unsaturated. hCritA: I do not have more to say in addition to what's written in the help. I would not change t...
by Jirka
Fri Jun 26, 2020 8:29 pm
Forum: HYDRUS (2D/3D)
Topic: Well as constant head
Replies: 9
Views: 1121

Re: Well as constant head

I'm pretty sure that "Pulse Duration" works OK if you use this option correct. Note the definition in the User Manual: " Pulse Duration: Time duration of the concentration pulse. Concentrations (flux or resident) along all boundaries, for which no time-variable boundary conditions are specified, are...
by Jirka
Thu Jun 25, 2020 6:52 pm
Forum: HYDRUS (2D/3D)
Topic: Well as constant head
Replies: 9
Views: 1121

Re: Well as constant head

What you say is not correct. The units for internal node recharge are [L2/T] (see the figure below) and [L3/T] in 2D and 3D, respectively. J.
NodalRecharge.png
NodalRecharge.png (18.53 KiB) Viewed 81 times
by Jirka
Thu Jun 25, 2020 6:44 pm
Forum: Hydrus 1D
Topic: Recharge estimation from pond
Replies: 1
Views: 43

Re: Recharge estimation from pond

Can you provide a schematic? J.
by Jirka
Wed Jun 24, 2020 2:26 pm
Forum: HYDRUS (2D/3D)
Topic: Well as constant head
Replies: 9
Views: 1121

Re: Well as constant head

Qp is the pumping rate (positive for removal of water, negative for adding water) ([L2 T–1] or [L3 T–1] for two-dimensional and axisymmetric systems, respectively). See Figure 2.7 in the technical manual or Fig. 1 in: Šimůnek, J., M. Šejna, and M. Th. van Genuchten, New Features of the Version 3 of ...
by Jirka
Fri Jun 19, 2020 8:20 pm
Forum: Hydrus 1D
Topic: Using HYDRUS-1D Upside down!
Replies: 1
Views: 62

Re: Using HYDRUS-1D Upside down!

1. Indeed, the decline from vertical axes is equal to 1, 0, -1 for vertical downward, horizontal, and vertical upward flow. It is the magnitude of gravity. You should be able to run in the inverse mode a project that has gravity=-1. 2. Evaporation is the solution of the surface energy balance equati...
by Jirka
Thu Jun 18, 2020 7:04 pm
Forum: Hydrus 1D
Topic: Solute concetration in drain discharge
Replies: 1
Views: 84

Re: Solute concetration in drain discharge

The standard HYDRUS module (but none of the specialized modules, such as HP1 or UnsatChem) has an option to choose if the drainage flux (to horizontal drains, qdrain) is applied at the bottom of the soil profile or vertically distributed along the saturated part of the soil profile. This is obviousl...
by Jirka
Wed Jun 17, 2020 2:28 pm
Forum: HP1 (HYDRUS-1D - PHREEQC)
Topic: Horizontal flow in Hydrus 1D
Replies: 1
Views: 68

Re: Horizontal flow in Hydrus 1D

Sure, we do not rotate the graph for horizontal flow and use the same ones as for vertical flow. You need to interpret the top in the graph as the left end, and the bottom as the right end. Similarly, top fluxes are the fluxes at the left side and the bottom fluxes at the right side. You can interpr...